Hi,

How can I tell if a gearbox has a OS Giken gearset? It is off the car and I am not sure how I can tell if it has one? Is there a quick way to check it without opening it up? As not sure if I will get a chance too?

 

Any help would be much Appreciated, I need to know fairly soon

 

This is the single turbo section. Not the section for this question

 

The only way you ca. Tell is by taking the lower gearbox plate off and see if the OS Giken name is on the shaft, then clean the plate and re seal it on, will take about 10 mons wart to finish. Obviously drop the gearbox oil out first

 

Drive the car. 1st gear on a stock FD will reach 41 mph at 8000 rpm. The 5 speed OS Giken gearset will hit 55 mph at 8000 rpm in 1st gear. The above mph estimates assume a 25 in overall diameter tire.

-Andrew

 

Where is the Lower gearbox plate? And what should I see? It's not in the car so I can't check by that method

 

Since the gearbox is out of the car, put it in each gear and rotate the input shaft and count the output shaft revolutions. X in to y out to calculate the ratios. It might take many X to get an accurate Y.

But after all it is simple logic and simple math.

 

What's stock and what's the os gikwn?

 

I have an OS Giken gearset in my FD. Externally you can't tell the difference at all.

If it's out of the car, you'll have to remove the lower trans pan (as you've already been told).

Then take a look and see if the parts look to be from OS Giken.

Who is selling the trans? Link? Reputable seller? Do they have a receipt?

 

If you went to the trouble of pulling the bottom cover, rather than monitoring shaft revolutions with the box intact - which I'd personally prefer to do! You can easily enough count teeth on the gears....white marker helps. First gear would probably be the easiest, with the larger change in ratio there ~ 3.483 to 2.578.